Lock device having position sensor

ABSTRACT

A position sensing system and method for detecting the displacement of a door from a reference position, such as, for example, from a closed position. The system includes a magnetometer that may be operably connected to the door, and which measures positional location relative to a reference magnetic field, such as, for example, a magnetic field provided by a magnet of a lock device. The system may also include an accelerometer that detects acceleration of the door, and thereby provides an indication of when location is to be measured by the magnetometer. Measurement information from the magnetometer is used to derive a position indicator that is compared to a reference indicator, the reference indicator being associated with the reference position. Differences between the position and reference indicators may provide an indication that the door has been moved from the reference position.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/786,015, filed on Oct. 17, 2017 and issued as U.S. Pat. No.10,227,818, which is a continuation of U.S. patent application Ser. No.14/711,414, filed on May 13, 2015 and issued as U.S. Pat. No. 9,790,736,which claims the benefit of U.S. Provisional Patent Application No.61/992,698, filed on May 13, 2014, the contents of each applicationhereby incorporated by reference in their entirety.

BACKGROUND

Embodiments of the present invention generally relate to lock deviceshaving position sensing capabilities. More particularly, embodiments ofthe present invention relate to lock devices having a magnetometer fordetection of a position of a door.

Security systems can monitor the position of a door, gate, panel, orother similar access barrier (collectively referred to herein as“doors”) relative to an associated entryway or structure. Suchpositional information may provide an indication as to whether the dooris positioned to prohibit or allow ingress or egress into/from theassociated entryway and/or structure. Certain types of monitoringsystems use a reed switch and magnet, wherein the reed switch is alteredbetween open and closed positions based on the location of the magnet.In at least some applications, the magnet may be mounted or otherwiseembedded in the door, while the reed switch is mounted in a door frame,or vice versa. When the door, and thus the magnet embedded therein, isin, or is brought into, close proximity to the reed switch, the reedswitch can be actuated. Conversely, the reed switch may be de-activatedwhen the door, and thus the magnet, is positioned, or is being moved,away from the reed switch. The activation and de-activation of the reedswitch may be monitored by corresponding circuitry. However, suchsecurity devices often require addition preparation and permanentmodification of the door and door frame, such as, for example,modification necessary for the secured placement of the magnet and reedswitch in/to the door or door frame. Such additional preparation andmodification can increase manufacturing and/or installation time andcosts. Further, unauthorized attempts to circumvent the monitoring ofthe reed switch may be achieved through the placement of another magnethaving sufficient magnetic strength to retain the reed switch in theactuated position as the door and associated embedded magnet are movedaway from the reed switch.

BRIEF SUMMARY

One embodiment is a unique system, components, and methods for a lockdevice having position sensor. Other embodiments include apparatuses,systems, devices, hardware, methods, and combinations for a lock devicehaving position sensor. This summary is not intended to identify key oressential features of the claimed subject matter, nor is it intended tobe used as an aid in limiting the scope of the claimed subject matter.Further embodiments, forms, objects, features, advantages, aspects, andbenefits shall become apparent from the following description anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying figureswherein like reference numerals refer to like parts throughout theseveral views, and wherein:

FIGS. 1 and 2 illustrate an example position sensing system used with adoor that may be moved between closed and open positions, and whichincludes a lock device having position sensing capabilities according toan illustrated embodiment of the present invention.

FIG. 3 illustrates a front view of an example strike assembly that issecured to a door frame and which provides a magnetic field for positionsensing according to an illustrated embodiment of the present invention.

FIG. 4 illustrates a cross sectional view of a strike assembly securedto door frame and which has a magnet that provides a reference magneticfield and according to an illustrated embodiment of the presentinvention.

FIG. 5 illustrates a schematic block diagram of a processing device andsensor of a lock device that is adapted for wireless communications withan access control system according to an illustrated embodiment of thepresent invention.

FIG. 6 illustrates a flow chart of an example method for detecting theposition of a door according to an illustrated embodiment of the presentinvention.

FIG. 7 illustrates a flow chart of another example method for detectingthe position of a door according to an illustrated embodiment of thepresent invention.

The foregoing summary, as well as the following detailed description ofcertain embodiments of the present invention, will be better understoodwhen read in conjunction with the appended drawings. For the purpose ofillustrating the invention, there is shown in the drawings, certainembodiments. It should be understood, however, that the presentinvention is not limited to the arrangements and instrumentalities shownin the attached drawings.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, any alterations and further modificationsin the illustrated embodiments, and any further applications of theprinciples of the invention as illustrated therein as would normallyoccur to one skilled in the art to which the invention relates arecontemplated herein.

FIGS. 1 and 2 illustrate a position sensing system 100 used with a door102 that may be moved between closed and open positions, and whichincludes a lock device 104 having position sensing capabilitiesaccording to an illustrated embodiment of the present invention.According to certain embodiments, the door 102 is operably mounted to adoor frame 106 or to an adjacent structure or wall 103, such as, forexample, by one or more hinges or tracks so that the door 106 may bemoved between a closed position (FIG. 1) and an open position (FIG. 2),as well as positions therebetween. Further, the door frame 106 maygenerally define at least a portion of a passageway 107 through whichindividuals and/or objects may pass.

The lock device 104 may be an electronic lock having a lock assemblyand/or latch assembly that may be generally known in the art.Additionally, at least a portion of the lock assembly and/or latchassembly may be contained within a housing 105 of the lock device 104.The housing 105 may be positioned on the door 102, door frame 106,and/or the wall 103 of the associated structure to which the door frame106 or door 102 is attached. In the illustrated embodiment, the lockdevice 104 includes a handle, knob, or lever 108 that is used todisplace a latching mechanism 110 of the latch assembly, such as, forexample, a deadbolt or latch. Further, the latching mechanism 110 mayextend through an orifice 111 of a door strike 112 (FIG. 3) of the lockdevice 104, and into at least a portion of the door frame 106 and/orwall 103. As shown in FIGS. 3 and 4, according to the illustratedembodiment, the door strike 112 may be operably secured to the doorframe 106, such as, for example, by one or more fasteners 113,including, for example, screws, bolts, or pins, among other fasteners.The interference provided by the latching mechanism 110 extendingthrough at least the door strike 112 may prevent the door 102 frommoving away from the closed position. However, when the lock device 104is in an unlocked condition, such as, for example, when the lock device104 is unlocked through the use of a key, card reader, or keypad 114,among other devices, the lever 108 may be rotated so as to withdraw atleast a portion of the latching mechanism 110 from the door strike 112and/or wall 103 or door frame 106. Moreover, when the lock device 104 isin the unlocked condition, the displacement of the lever 108 maytranslate into the lock assembly displacing at least a portion of andlatch assembly so that a sufficient portion of the latching mechanism110 is withdrawn into the door 102 and/or latch assembly so that thelatching mechanism 110 does not prevent the door 102 from being movedaway from the closed position.

Referencing FIG. 5, according to certain embodiments, the lock device104 may include a processing device 116, an input/output device 117, asensor 118, and a transceiver 130. The processing device 116 can be aprogrammable type, a dedicated, hardwired state machine, or anycombination of these. The processing device 116 may further includemultiple processors, Arithmetic-Logic Units (ALUs), Central ProcessingUnits (CPUs), Digital Signal Processors (DSPs), or the like. Processingdevices 116 with multiple processing units may utilize distributed,pipelined, and/or parallel processing. The processing device 116 may bededicated to performance of just the operations described herein or maybe utilized in one or more additional applications. In the depictedform, the processing device 116 is of a programmable variety thatexecutes algorithms and processes data in accordance with operatinglogic 119 as defined by programming instructions (such as software orfirmware) stored in a memory 121. Alternatively or additionally, theoperating logic 119 for the processing device 116 is at least partiallydefined by hardwired logic or other hardware. The processing device 116may include one or more components of any type suitable to process thesignals received from the input/output device 117, such as, for example,the keypad 114, or elsewhere, and to provide desired output signals.Such components may include digital circuitry, analog circuitry, or acombination of both.

The memory 121 may be of one or more types, such as a solid-statevariety, electromagnetic variety, optical variety, or a combination ofthese forms. Furthermore, the memory 121 can be volatile, nonvolatile,or a combination of these types, and some or all of the memory 121 canbe of a portable variety, such as a disk, tape, memory stick, cartridge,or the like. In addition, the memory 121 can store data that ismanipulated by the operating logic 121 of processing device 116, such asdata representative of signals received from and/or sent to theinput/output device 117 in addition to or in lieu of storing programminginstructions defining the operating logic 119, just to name one example.As shown in FIG. 5, the memory 121 may be included with the processingdevice 116 and/or coupled to the processing device 116.

The processing device 116 may be configured to control a number ofoperations of the lock device 104, such as, for example, confirmingwhether information has been entered into the input/output 117, such as,for example, a correct code has been entered using the keypad 114 tounlock the lock device 104 so that the door 102 may be moved away fromthe closed position.

The sensor 118 includes a magnetometer 120 that is configured to measurea magnetic field so as to provide an indication of the position ororientation of the magnetometer 120 relative to the magnetic field, andthereby provide an indication of the position of the door 102. Accordingto certain embodiments, the measurements provided by the magnetometer120 may be a one, two, and/or three dimensional quantity and/or scalarvalue(s), such as, for example, scalar measurements along each of thethree x-y-z directional axes shown in FIG. 1. Additionally, as theposition of the magnetometer 120 changes relative to the referencemagnetic field, the value(s) of the scalar measurements change as well,as measured by the magnetometer 120. The sensor 118 may be referred toas a door position sensor (DPS).

One or more sets of measurements provided by the magnetometer 120 may beused to derive a position indicator that is indicative of the locationof the magnetometer 120 and/or door 102. For example, according tocertain embodiments, the magnetometer 120 may conduct a measurement todetermine a measurement set, such as, for example, a scalar value alongone or more axes. In other embodiments, the measurement(s) from themagnetometer 120 may be used to calculate a one-dimensional,two-dimensional, and/or three-dimensional vector that may be used todetermine changes in the magnetometer's position relative to themagnetic field. Further, the magnetometer 120 may be configured toobtain multiple sets of measurements within a predetermined period oftime, such as, for example, five sets of measurements within one secondor less. According to certain embodiments, the multiple sets ofmeasurements may then be filtered to remove potential noise such as, forexample, high frequency noise and/or to account for potential changes inmeasurements from the magnetometer 120 and/or the reference indicatorbased on differences in temperature. For example, multiple sets ofmeasurements may be filtered by using at least some, if not all, of thesets of measurements to attain an average measurement(s), such as, forexample, a single or multiple average scalar value(s). Further,according to certain embodiments, before or after averaging, themeasured values of a single set or multiple sets of measurements may becombined together, such as, for example, by adding some or all of themeasured scalar values to obtain a single value for the positionindicator. Further, if necessary, according to certain embodiments, themeasured value(s) may be converted to an absolute value before beingused to obtain the position indicator.

According to certain embodiments, the processing device 116 may utilizean algorithm to evaluate the position indicator to determine theposition, or change in position, of the magnetometer 120 and/or door102. Moreover, the processing device 116 may be adapted to compare oneor more position indicators with a calibrated or reference positionindicator. The reference position indicator may reflect a known orparticular position indicator, such as being a position indicatorassociated with the door 102 being at a reference location, including,for example, the door 102 being in the closed position. Thus, accordingto certain embodiments, the processing device 116 may determine whetherthe value(s) of the position indicator is/are at least generally thesame as the reference indicator. If the value(s) of the positionindicator are not generally the same as the reference indicator, orwithin a predetermined range of values for the reference indicator, thenaccording to certain embodiments, the processing device 116 maydetermine the door 102 is not in the reference position, such as, forexample, the door 102 not being in the closed position. According toother embodiments, the processing device 116 may also be configured todetermine the particular location of the magnetometer 120 and/or door102, such as, for example, the particular location of the magnetometer120 and/or door 102 relative to the reference position.

The sensor 118 may be calibrated during the lock commissioning processto establish a “home” reference position. In some embodiments, thereference position is a rolling average of 10 samples on each axis. Atthe time of calibration, all 10 samples may be immediately taken fromthe magnetometer and samples are updated over time. The followingequation may be utilized for initial calibration:

$\begin{matrix}{{x_{h} = {\frac{1}{10}{\sum\limits_{i = 0}^{10}\; x_{i}}}},{y_{h} = {\frac{1}{10}{\sum\limits_{i = 0}^{10}\; y_{i}}}},{z_{h} = {\frac{1}{10}{\sum\limits_{i = 0}^{10}\; z_{i}}}}} & (1)\end{matrix}$

Once calibrated, the sensor 118 may begin to take measurements on aperiodic basis. To maximize battery life and sensor performance, ameasurement interval of three seconds may be used. The lock device 104will wake up every three seconds to measure each of the three axes andcompare the results to the reference position. When the door 102 is inthe closed state, the absolute value of the difference between thecurrent reading (x, y, z) and the reference position (x_(h), y_(h),z_(h)) may be summed together into one value. The following equation maybe used to determine when the door 102 is closed:Mag_(closed)=abs(x−x _(h))+abs(y−y _(h))+abs(z−z _(h))  (2)

Using the absolute value removed any sign variations in the measureddata. All variations from the reference point (positive or negative)result in an addition from the reference point. The equation above is ata minimum typically only when the measured point is relatively veryclose to the reference point. The resulting value is compared againstset thresholds to determine the position of the door 102. While the door102 is closed, the algorithm modifies the reference position value via arolling average using the measured values. This rolling averagecomputation allows for temperature and environmental changes experiencedby the sensor to be captured in the algorithm. This allows for thesystem to respond to changes without the customer having to re-calibratethe system on a periodic basis.

Once the system detects that the door 102 has been opened, the systemwill continue to measure the door position every three seconds. However,there are additional corrections added to the reference position toaccount for temperature drifts seen by the sensor (e.g., themagnetometer 120). One example is the case where a door is opened andsubjected to direct sunlight for the day. The lock device 104 willexperience thermal loading from the sun and will change the response ofthe magnetometer 120. When the door 102 is closed, the magnetometer 120will measure a different reading for the closed position. Thermaltesting of the sensor showed a linear relationship between the outputand the temperature change. When initially calibrated, the lock device104 recorded the temperature. The reference position is temperaturecompensated, as well as the overall value as shown in the equation belowwhich may be used when the door is open:Mag_(open)=abs(x−x _(h)′)+abs(y−y _(h)′)+abs(z−z _(h)′)−(4*abs(T−T_(h)))  (3)

x_(h)′=x_(h)+2(T−T_(h))

y_(h)′=y_(h)+2(T−T_(h))

z_(h)′=z_(h)+2(T−T_(h))

Once the lock device 104 has determined that the door has been closed,the reference position may be replaced with the current reading, and thesystem reverts to the “door closed” processing of the sensor data(equation 2). Typically, the reference position is not updated while thedoor 102 is open. The rolling average may be applied to the referenceposition only when the door 102 is closed.

The lock device 104 may maintain a state machine of door positions.These states may include: (1) door originally open and still is open;(2) door originally closed and now is open; (3) door originally open andnow is closed; (4) door originally closed and still is closed; and (5)door has a magnetic tamper. These states allow the lock device 104 toknow when the door transitions versus reporting the same informationmultiple times due to the three second sampling rate. The lock device104 may use these states to decide if the door is open or closed and ifnecessary, report “Forced Door,” “Propped Door,” or “Magnetic Tamper” toan access control system.

The lock device 104 may also output various status messages to an accesscontrol system such as “Door Open”, “Door Closed”, “Forced Door”,“Propped Door”, and “Magnetic Tamper”. “Door Open” and “Door Closed”have been previously described.

A “Forced Door” condition is when the lock device 104 detects that thedoor has been opened, but no valid card presentation or Request to Exit(REX) signal was detected. The most common cause of a “Forced Door” isthe use of a mechanical key to access the door. A REX signal isgenerated when an individual turns the handle of the door leave from thesecure area.

A “Propped Door” event is triggered when a door has been openednormally, but not closed within a set timeframe. The time needed toregister a propped door is a configurable setting in the lock device104. The lock device 104 may record one propped door event in the auditlog for each time the door is left open.

A “Magnetic Tamper” is typically registered when a relatively largemagnetic field was detected by the magnetometer 120. This could becaused by a person presenting a large magnet in order to try and foolthe door into being open or closed. The tamper notice may be recorded inorder to notify the user of the access control system that the door mayneed to be recalibrated. If the magnetic field was strong enough, itcould permanently change the environment of the sensor, and cause falsereadings. False readings typically would indicate that the door was openwhen it is not. However, it should be virtually impossible for anexternal magnetic field to be produced that will fool the door intothinking it is closed when it is open. This is due to the fact that thethree axes are measured independently, and would require an exactreplica in all three dimensions for the lock device 104 to think thedoor is closed when the door is not.

According to certain embodiments, the reference indicator may be storedin the memory 119 of the processing device 116. Further, the referenceindicator may be provided with a certain degree of discrepancy ortolerance so as to account for potential variations of the exactposition of the magnetometer 120 relative to the magnet 122 and/or theassociated magnetic field 126 when the door 102 is in the closedposition. Thus, according to certain embodiments, the referenceindicator may comprise a range of reference indicator values that aregenerally indicative of the door 102 being in the reference position.Additionally, the reference indicator may be obtained or calibrated at anumber of different time periods, such as, for example, duringinstallation of the lock device 102 or during of maintenance of the lockdevice.

The magnetometer 120 may be located at a variety of different locations,such as, for example, being part of the lock device 104 that is operablyconnected to the door 102, or being secured to the door frame 106 orwall 103. According to embodiments in which the magnetometer 120 isoperably secured to the door 102, such as being contained in a housing105 that is secured to the door 102, the magnetometer 120 measurechanges in the position of the magnetometer 120 relative to a referencemagnetic field as the door 102 is moved. Alternatively, according toembodiments in which the location of the magnetometer 120 remainsgenerally static, such as, for example, when the magnetometer 120 ishoused or mounted to the door frame 106 or wall 103, the magnetometer120 may sense changes in the location of the reference magnetic fieldrelative to the magnetometer 120, such as, for example, when thereference magnetic field is a magnet that is attached to, and thus isdisplaced with, the door 102.

The reference magnetic field may be provided by a variety of differentmagnetic or magnetized sources. For example, according to certainembodiments, the magnetometer 120 may have a sensitivity and/orresolution that allow the reference magnetic field to be the magneticfield of the earth. According to such embodiments, the magnetometer 120may be operably secured to the door 102 such that the measurementsprovided by the magnetometer 120 reflect changes, if any, in thelocation of the magnetometer 120, and thus the door 102, relative to theearth's magnetic field.

Alternatively, as shown in FIG. 4, according to other embodiments, thereference magnetic field is provided by a magnet 122 that is part of thelock device 104, or is positioned in the associated door frame 106, wall103, or other location associated with the passageway 107. For example,in the illustrated embodiment, the reference magnetic field 126 isprovided by door strike assembly 109 that includes a magnet 122 that isoperably connected to and/or part of, a door strike 112, such as, forexample, connected to the door strike 112 by a mechanical fastener,including a pin, bolt, or screw, a weld, an adhesive, or a bracket,among other connections. Further, in the illustrated embodiment, themagnet 122 is shown as attached to an inner sidewall 124 b of the doorstrike 112, which may minimize the potential of the magnet 122interfering with the displacement of the door 102. However, the magnet122 may be positioned in a variety of different locations on or in thedoor strike 112, such as, for example, in a portion of the door strikebetween and/or adjacent to an outer sidewall 124 a and an inner sidewall124 b of the door strike 112. Additionally, according to certainembodiments, at least a portion of the door strike 112 may beconstructed from a magnetic or magnetized material that may provide thereference magnetic field 123.

For example, according to such embodiments, a reference indicator may bebased on measurements obtained by the magnetometer 120 of the referencemagnetic field 126 of the magnet 122 when the door 102 is in the closedposition (FIG. 1). Moreover, the processing device 116 may use themeasurement(s) from the magnetometer 120 to derive the referenceindicator. During subsequent use, during predetermined intervals oftime, or upon sensing movement, acceleration, and/or vibrations of thedoor 102, the magnetometer 120 may attain one or more sets ofmeasurements that are used by the magnetometer 120 and/or processingunit 116 to derive a position indicator. The derived position indicatormay then be compared to the reference indicator to determine whether thedoor 102 has been displaced from the reference position, which in thisexample is the closed position.

According to certain embodiments, the processing device 116 may beconfigured to evaluate whether differences or discrepancies between aposition indicator and the reference indicator are/were authorized. Forexample, according to embodiments in which the reference indicator isreflective of the door 102 being in the closed position, each time thedoor 102 is subsequently opened, the position indicator will typicallybe different than the reference indicator. Thus, the processing device116 may be configured to evaluate whether authorization event has or hasnot occurred before determining whether differences or discrepancies inthe position indicator and reference indicator are to be evaluatedand/or are to be communicated to an access control system 128, asdiscussed below. For example, according to certain embodiments, anauthorization event may occur by the authorized unlocking of the lockdevice 104, such as, for example, by an authorized key, card, or codebeing entered into and/or read by the input/output device 117.Alternatively, the authorization event may be a signal received from anaccess control system 128 indicating that the change in position of thedoor 102, such as, for example, the opening of the door 102, is or willbe authorized. If the differences between the position indicator and thereference indicator occurred in connection with an authorized event,then according to certain embodiments, the processing device 116 maydeem such differences are not associated with unauthorized opening ofthe door 102.

In the absence of an authorization event, the processing device 116 maybe configured to communicate to the access control system 128 instancesin which the position indicator is different than the referenceindicator. For example, the controller 105 may include, or be operablyconnected to, a transceiver 130 that transmits a wireless status signalindicative of the occurrence of a difference, or other discrepancies, ina position indicator and the reference indicator to a transceiver 132 ofthe access control system 128. According to certain embodiments, theaccess control system 128, such as, for example, a processing device 134of the access control system 128, may then evaluate whether there is anyindication of the occurrence of an authorization event. Further, theaccess control system 128 may issue a command relating to the issuanceof a communication of a potential security breach, such, as, forexample, by issue commands relating to commencing an audible and/orvisual alarm, or issuance of a text message, among other types ofcommunications.

Referencing FIG. 5, according to certain embodiments, the sensor 118 mayalso include an accelerometer 136. The accelerometer 136 may be part of,or separate from, the magnetometer 120. A variety of different types ofaccelerometers 136 may be employed. Further, the accelerometer 136 maydetect acceleration in a single-axis or among two more axes.Accordingly, the accelerometer 136 may measure acceleration and/orvibrations as one or more vector or scalar quantity(ies). Theaccelerometer 136 may be adapted to at least assist in controlling thesupply of power to the magnetometer 120 so as to converse power when theposition of the door 102 is generally relatively static. For example,according to certain embodiments, the accelerometer 136 is adapted to beused with the algorithm of the magnetometer 120 so that relatively lowpower modes are implemented for the magnetometer 120 during periods ofgeneral inactivity, such as, for example, when the position of the door102 has not changed within a predetermined time period. According tosuch embodiments, the detection of an acceleration and/or vibration bythe accelerometer 136 may trigger the issuance of a wake-up command forthe magnetometer 120 that awakes the magnetometer 120 and/or causes themagnetometer 120 to take a measurement(s) indicative of the position ofthe door 102.

Further, according to certain embodiments, the wake up command for themagnetometer 120 may issue when the measured acceleration or vibrationsby the accelerometer 136 exceed a predetermined limit. For example, thesensitivity of the accelerometer 136 may be adapted, and/or the sensor118 may be configured, to at least attempt to generally control thetypes or sizes of acceleration forces that may trigger a wake-upcommand. For example, the accelerometer 136 and/or the sensor 118 may beadapted so that vibrations felt from the closing of other doors,relatively minor touching or contact with the door 102, and/or door 102movement caused by relatively mild wind forces will or will not resultin a wake-up command being issued to the magnetometer 120.

According to certain embodiments, periodic polling signals may betransmitted from the processing device 116 to the magnetometer 120 thatat least occasionally awake the magnetometer 120 from the sleep mode.For example, according to certain embodiments, the processing device 116generates a wake-up signal for the magnetometer 120 every three seconds.However, the frequency at which the polling signal is provided to themagnetometer 120 may vary for different embodiments and/or applications.When awoken, the magnetometer 120 may conduct one or more sets ofmeasurements reflecting the position of the magnetometer 120, and thusthe door 102, relative to the reference magnetic field 123 so that thelocation of the door 102 may be verified. For example, when awoken, thepositioned of the door 102, as indicated by the measurements provided bythe magnetometer 120, may again be used to determine and/or verify thepresent position indicator of the magnetometer 120, and thus, the door102. In the event that, after being awoken, the position indicator isdifferent than the reference indication and/or is different than anexpected position indicator, the transceiver 130 of the controller 105may transmit the detected difference to the access control system 128via the transceivers 130, 132, as previously discussed.

FIG. 6 illustrates a flow chart of a method 200 for detecting theposition of the door 102 according to an illustrated embodiment of thepresent invention. While FIG. 6 is shown and described herein ascontaining certain steps, according to other embodiments, certain stepsmay be removed and/or added. Additionally, according to certainembodiments, the order in which steps occur may be different fordifferent embodiments. According to the illustrated embodiment, at step202, a reference indicator that corresponds to a reference location ofthe magnetometer 120, and thus the location of the door 102, may beobtained. For example, as previously discussed, according to certainembodiments, the reference location may be the location of the door 102when the door 102 is in the closed position. Further, again, thereference indicator may be obtained by the magnetometer 120 obtaining ameasurement based on a reference magnetic field 126, such as, forexample, the magnetic field of the earth or of a magnet 122 that isoperably connected to, or part of the lock device 104. Further, thereference indicator 202 may be obtained at a variety of different times,including, for example, during installation of the lock device 104 on adoor 102 that has been operably connected to the door frame 106.

At step 204, a determination may be made as to whether the door 102 hasbeen moved or if predetermined period of time has elapsed since themagnetometer 120 obtained a measurement(s). For example, according tothe illustrated embodiment, the accelerometer 136 may sense anacceleration and/or vibration that is indicative of the movement of thedoor 102. If motion has been detected, a wake-up signal, if needed, orother signal indicating a request for a position indicator may be sent,for example by the sensor 118 and/or processing device 116, to themagnetometer 120. Accordingly, at step 206, the magnetometer 120 mayobtain one or more measurements based on the location of themagnetometer 120 relative to the reference magnetic field 126. Theobtained measurements may then be used to derive a position indicator(s)by the magnetometer 120 or the processing device 116, as previouslydiscussed.

However, if at step 204 there is a determination that the door has notmoved within a predetermined time period, then at step 208 at least themagnetometer 120 may enter a lower power or energy conservation mode,such as, for example a sleep mode. The magnetometer 120 may then remainin a sleep mode until either acceleration, vibration, or motion of thedoor 102 is directly or indirectly detected, such as, for example, viathe accelerometer 136, at step 210, or the time during which themagnetometer 120 has remained in the sleep mode exceeds a certain timelimit, as indicated by step 212. However, if the sensor 118 provides anindication of displacement of the door, or if the magnetometer 120 hasbeen in a sleep mode for a predetermined period of time, then, at step206, the magnetometer 120 is to obtain a measurement reflecting thelocation of the magnetometer 120 and/or door, as previously discussed.

At step 214, the position indicator obtained at step 206 is compared bythe processing device 116 with the reference indicator from step 202. Ifthere is no difference between the position indicator and the referenceindicator, or a range of acceptable values for the reference indicator,then the method may return to step 204, wherein the sensor 118 may stillbe activated for either a predetermined period of time before enteringthe sleep mode, or until subsequent displacement, acceleration, and/orvibration of the door 102 is detected. If however, the positionindicator is different than the reference indicator so as to indicatethat the door 102 is not in the reference position, then at step 216,the processing device 116 or access control system 128 may determinewhether the position indicator is associated with an authorizationevent. If the position indicator is determined to be associated with anauthorization event, then the process may again return to step 204.However, if the change in position of the door 102 is not associatedwith an authorization event, then at step 220 the access control system128 may communicate a signal indicative of the change in position of thedoor 102, and thus the possible unauthorized ingress/egress through thepassageway 107.

FIG. 7 is flow chart of another example method 300 for detecting theposition of the door 102 according to an illustrated embodiment of thepresent invention. While FIG. 7 is shown and described herein ascontaining certain steps, according to other embodiments, certain stepsmay be removed and/or added. Additionally, according to certainembodiments, the order in which steps occur may be different fordifferent embodiments.

At step 302, the sensor 118 is calibrated as described above. Next, atstep 304, the temperature and x, y, z axes home positions are saved inthe lock device 104. At step 306, the lock device 104 reports that thedoor is closed. Next, at step 308, a wakeup time is scheduled for themagnetometer 120 to take a measurement of the door position. At step310, the lock device 104 and/or the sensor 118 power down or go into alow power mode.

Next, at step 312, the lock device 104 determines whether a valid cardwas detected. If a valid card was presented, then lock device 104 and/orthe sensor 118 power down. If not, the method 300 proceeds to step 316where it is determined whether a REX signal was received. If a REXsignal was received, then method 300 proceeds to step 314 and the lockdevice 104 and/or sensor 118 are powered down. Otherwise, method 300proceeds to step 318 in which it is determined whether a sensor delayhas expired. If the delay has not expired, then method 300 proceeds tostep 310. If the delay has expired, then method 300 proceeds to step 320in which the lock device 104 schedules a wakeup time.

Next, at step 322, another measurement of door position is taken usingthe magnetometer 120. At step 324, the lock device 104 determineswhether the door 102 is open. If the door 102 is not open, the lockdevice 104 proceeds to step 326 in which door closed is reported andthen at step 328, the lock device 104 computes a home rolling averagebased on the new measurement and method 300 proceeds to step 310.

Returning to step 324, if the lock device 104 determines that the dooris open, method 300 proceeds to step 330 in which a door open statusmessage is reported to an access control system. Next, method 300proceeds to step 332 in which a forced door alert is reported to anaccess control system. Method 300 proceeds to step 314 in which the lockdevice 104 and/or the sensor 118 are powered down.

Method 300 then proceeds to step 334 in which it is determined whether aDPS delay has expired. If the delay has not expired, then method 300proceeds to step 314. If the delay has expired, then method 300 proceedsto step 336 in which a wakeup time is scheduled. Next, in step 338, themagnetometer 120 takes a measurement. Next, in step 340, the temperaturecalibration is applied to the measurements.

Method 300 then proceeds to step 342 in which the lock device 104determines whether the door 102 is open. If the door is not open, method300 proceeds to step 344 in which a door closed is reported to theaccess control system. Next, method 300 proceeds to step 346 in whichthe rolling home average is reset with the current closed reading. Next,method 300 proceeds to step 310.

Returning to step 342, if the door 102 is open, method 300 proceeds tostep 348 in which a door open is reported to an access control system.Next, in step 350, the lock device 104 determines whether there is apropped door. If there is no propped door, method 300 proceeds to step314. If there is a propped door, method 300 proceeds to step 352 todetermine whether an audit is recorded. If an audit is recorded, thenmethod 300 proceeds to step 314. If no audit is recorded, then method300 proceeds to step 354 in which a propped door audit is recorded.Method 300 then proceeds to step 314.

An aspect of the present invention is a lock device that includes amagnet that provides a reference magnetic field and a magnetometer thatis structured to measure a location of the magnetometer relative to thereference magnetic field. The lock device also includes a processingdevice that is structured to execute instructions stored on anon-transitory computer readable medium that cause the processing deviceto receive the location measurement of the magnetometer, derive aposition indicator from the location measurement of the magnetometer,and compare the position indicator to a reference indicator thatcorresponds to the location of the magnetometer when the magnetometer isat a reference position. Additionally, the processing device is adaptedto determine, based on the comparison of the position indicator to thereference indicator, whether the magnetometer is at the referenceposition.

Another aspect of the present invention is a position sensing system fordetecting the displacement of a door from a closed position. Theposition sensing system includes a lock device that has a latchmechanism and a door strike. Additionally, the position sensing systemincludes a magnet that provides a reference magnetic field and a sensorhaving a magnetometer and an accelerometer. The magnetometer isconfigured to measure a location of the magnetometer relative to thereference magnetic field, while the accelerometer is configured todetect an acceleration of the door. The position sensing system alsoincludes a processing device that is configured to derive a positionindicator from the location measured by the magnetometer. The processingdevice is further configured to compare the position indicator to areference indicator, the reference indicator being indicative of thelocation of the magnetometer when the door is in the closed position.

Additionally, another aspect of the present invention is a method fordetermining whether a door has been displaced from a reference position.The method includes measuring a reference location of a magnetometerrelative to a reference magnetic field when the door is at the referenceposition and deriving, by a processing device of a lock device, areference indicator from the measured reference location. Further, thereference indicator is recorded in the memory of the lock device. Themethod further includes detecting, by an accelerometer, an accelerationof the door and measuring, by the magnetometer and following detectionof the acceleration of the door, a position location of the magnetometerrelative to the reference magnetic field. The processing device derivesa position indicator from the measured position location compares theposition indicator and the reference indicator. The processing devicealso determines, from the comparison of the position indicator and thereference indicator, whether the door has been displaced from thereference position.

One aspect of the present application includes a lock device comprising:a magnet, the magnet providing a reference magnetic field; amagnetometer structured to measure a location of the magnetometerrelative to the reference magnetic field; and a processing devicestructured to execute instructions stored on a non-transitory computerreadable medium that cause the processing device to: receive thelocation measurement of the magnetometer; derive a position indicatorfrom the location measurement of the magnetometer; compare the positionindicator to a reference indicator, the reference indicatorcorresponding to the location of the magnetometer when the magnetometeris at a reference position; and determine, based on the comparison ofthe position indicator to the reference indicator, whether themagnetometer is at the reference position.

Features of the aspect may include: an accelerometer structured todetect an acceleration of the lock device, the processing device beingfurther structured to generate a signal to wake-up the magnetometer froma low power mode in response to detection of the acceleration; a doorstrike, and wherein the magnet is operably connected to the door strike;wherein the accelerometer and the magnetometer are included in the samechip; wherein the lock device includes a latching mechanism having atleast one of a latch and a deadbolt; wherein the processing device isstructured to transmit, via a wireless transceiver, a status message toan access control system, wherein the status message indicates whetherthe magnetometer has been displaced from the reference position; whereinthe location measured by the magnetometer is a plurality of scalarvalues along two or more axes; wherein the position indicator is a sumvalue of the measurements of the location measured by the magnetometer;wherein the processing device is adapted to issue a polling signal tothe magnetometer at predetermined time intervals.

Another aspect of the present application includes a position sensingsystem for detecting the displacement of a door from a closed position,the position sensing system comprising: a lock device having a latchmechanism and a door strike; a magnet, the magnet providing a referencemagnetic field; a sensor having a magnetometer and an accelerometer, themagnetometer configured to measure a location of the magnetometerrelative to the reference magnetic field, the accelerometer configuredto detect an acceleration of the door; and a processing devicestructured to derive a position indicator from the location measured bythe magnetometer, the processing device further configured to comparethe position indicator to a reference indicator, the reference indicatorindicative of the location of the magnetometer when the door is in theclosed position.

Features of the aspect may include: wherein the sensor is operablymounted to the door; wherein the magnet is operably connected to thedoor strike; wherein the magnetometer is operably connected to arelatively static structure adjacent to the door, and wherein the magnetis operably connected to the door; further including a transceiverconfigured to receive a signal from the processing device indicative ofthe position indicator being different than the reference indicator, andwherein the transceiver is configured to transmit a status signalindicative of there being a difference between the position andreference indicators to an access control system; wherein the locationmeasured by the magnetometer is a plurality of scalar values along twoor more axes; wherein the position indicator is a sum value of themeasurements of the location provided by the magnetometer; wherein theposition indicator is an average sum of a plurality of measurements ofthe location provided by the magnetometer; wherein the processing deviceis further configured to generate, at predetermined time intervals, apolling signal to wake the magnetometer from a lower power mode.

Yet another aspect of the present application includes a method fordetermining whether a door has been displaced from a reference position,the method comprising: measuring a reference location of a magnetometerrelative to a reference magnetic field when the door is at the referenceposition; deriving, by a processing device of a lock device, a referenceindicator from the measured reference location; recording in the memoryof the lock device the reference indicator; detecting, by anaccelerometer, an acceleration of the door; measuring, by themagnetometer and following detection of the acceleration of the door, aposition location of the magnetometer relative to the reference magneticfield; deriving, by the processing device, a position indicator from themeasured position location; and comparing, by the processing device, theposition indicator and the reference indicator; and determining, by theprocessing device, from the comparison of the position and referenceindicators whether the door has been displaced from the referenceposition.

Features of the aspect may include: the step of entering, by themagnetometer, a lower power mode after acceleration of the door has notbeen detected by the accelerometer for a predetermined period of time;the step of delivering a polling signal to the magnetometer to wake themagnetometer from a low power mode, and, whereupon awakening, the methodfurther includes measuring, by the magnetometer, a position location;wherein the step of measuring the position location includes measuringtwo or more scalar values indicative of the location of the magnetometerrelative to the reference magnetic field; wherein the step of derivingthe position indicator comprises adding together the two or more scalarvalues to obtain the position indicator; wherein the step of measuringthe position location includes obtaining a plurality of sets ofmeasurements of the position location, each of the plurality of sets ofmeasurements having two or more scalar values indicative of the locationof the magnetometer relative to the reference magnetic field; the stepof filtering the plurality of sets of measurements of the positionlocation; wherein the step of filtering is adapted to remove at leastone high frequency noise; wherein the step of deriving the positionindicator comprises obtaining an average value for the plurality of setsof measurements.

Another aspect of the present application includes a method fordetermining whether a door has been displaced from a reference position,the method comprising: measuring a reference location of a magnetometerrelative to a reference magnetic field when the door is at the referenceposition; deriving, by a processing device of a lock device, a referenceindicator from the measured reference location; recording in the memoryof the lock device the reference indicator; measuring, by themagnetometer, a position location of the magnetometer relative to thereference magnetic field; deriving, by the processing device, a positionindicator from the measured position location; comparing, by theprocessing device, the position indicator and the reference indicator;and determining, by the processing device, from the comparison of theposition and reference indicators whether the door has been displacedfrom the reference position.

Features of the aspect may include: the step of delivering a pollingsignal to the magnetometer to wake the magnetometer from a low powermode, and, whereupon awakening, the method further includes measuring,by the magnetometer, a position location; wherein the step of measuringthe position location includes obtaining a plurality of sets ofmeasurements of the position location, each of the plurality of sets ofmeasurements having two or more scalar values indicative of the locationof the magnetometer relative to the reference magnetic field; the stepof filtering the plurality of sets of measurements of the positionlocation; wherein the step of filtering is adapted to remove at leastone high frequency noise.

Various features and advantages of the present invention are set forthin the following claims. Additionally, changes and modifications to thedescribed embodiments described herein will be apparent to those skilledin the art, and such changes and modifications can be made withoutdeparting from the spirit and scope of the present invention and withoutdiminishing its intended advantages. While the present invention hasbeen illustrated and described in detail in the drawings and foregoingdescription, the same is to be considered illustrative and notrestrictive in character, it being understood that only selectedembodiments have been shown and described and that all changes,equivalents, and modifications that come within the scope of theinventions described herein or defined by the following claims aredesired to be protected.

While the invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the invention without departing from its scope.Therefore, it is intended that the invention not be limited to theparticular embodiment disclosed, but that the invention will include allembodiments falling within the scope of the appended claims.

The invention claimed is:
 1. A method for determining whether a door hasbeen displaced from a reference position relative to a door frame via alock device secured to the door, the method comprising: measuring,during calibration of the lock device, a reference location of amagnetometer of the lock device relative to a reference magnetic fieldwhen the door is at the reference position, wherein the referencemagnetic field is earth's magnetic field; deriving, by a processingdevice of the lock device, a reference indicator from the measuredreference location; recording, in memory of the lock device, thereference indicator; measuring, by the magnetometer and subsequent tocalibration of the lock device, a position location of the magnetometerrelative to the door frame based on the reference magnetic field;deriving, by the processing device, a position indicator from themeasured position location; comparing, by the processing device, theposition indicator and the reference indicator; and determining, by theprocessing device and from the comparing of the position indicator andreference indicator, whether the door has been displaced from thereference position.
 2. The method of claim 1, wherein the measuring ofthe position location of the magnetometer includes obtaining a pluralityof sets of measurements of the position location, and wherein each ofthe plurality of sets of measurements have two or more values indicativeof the location of the magnetometer relative to the reference magneticfield.
 3. The method of claim 1, further comprising waking themagnetometer from a sleep mode based on information generated by anaccelerometer of the lock device.
 4. The method of claim 1, wherein thedoor frame is a door frame of a building.
 5. A method for determiningwhether a door has been displaced from a reference position relative toa door frame via a lock device secured to the door, the methodcomprising: sensing, by a magnetometer of the lock device, a location ofthe magnetometer relative to a reference magnetic field, wherein thereference magnetic field is earth's magnetic field; determining aposition indicator based on the location of the magnetometer relative tothe reference magnetic field; and determining whether the door is in thereference position based on a comparison of the position indicator to areference indicator, wherein the reference indicator is indicative of alocation of the magnetometer when the door is in the reference position.6. The method of claim 5, wherein the reference position is a closedposition of the door.
 7. The method of claim 6, wherein the closedposition is a position in which a latch mechanism of the lock device iscapable of extending into a door strike mounted to the door frame. 8.The method of claim 5, wherein the determining of the position indicatorand the determining whether the door is in the reference position areperformed by a processing device of the door lock.
 9. The method ofclaim 5, wherein the door frame is a static structure.
 10. A lock deviceconfigured to be mounted to a door having an open position, a closedposition, and positions therebetween with respect to an adjacentstructure defining an entryway, the lock device comprising: a housingconfigured for mounting to the door; a latch mechanism movably mountedto the housing and operable to engage the adjacent structure to retainthe door in the closed position; a magnetometer structured to measure alocation of the magnetometer relative to a reference magnetic field,wherein the reference magnetic field is earth's magnetic field; aprocessing device structured to execute instructions stored on anon-transitory computer readable medium that causes the processingdevice to: receive the measured location of the magnetometer; derive aposition indicator from the measured location of the magnetometer,wherein the position indicator indicates one of the positions of thedoor with respect to the adjacent structure; compare the positionindicator to a reference indicator, the reference indicatorcorresponding to a location of the magnetometer with respect to thereference magnetic field when the magnetometer is at a referenceposition; and determine, based on the comparison of the positionindicator to the reference indicator, whether the magnetometer is at thereference position.
 11. The lock device of claim 10, wherein theinstructions further cause the processing device to generate thereference indicator while the lock device is in a calibration mode. 12.The lock device of claim 11, wherein the instructions further cause theprocessing device to generate the reference indicator based on themeasured location of the magnetometer while the lock device is in thecalibration mode.
 13. The lock device of claim 10, further comprising atransceiver configured to receive a signal from the processing deviceindicative of the position indicator being different from the referenceindicator, and wherein the transceiver is configured to transmit to anaccess control system a status signal indicative of there being adifference between the position indicator and the reference indicator.14. The lock device of claim 10, further comprising an accelerometer,wherein the processing device is configured to wake the magnetometerfrom a sleep mode based on information received from the accelerometer.15. The lock device of claim 10, wherein the magnetometer and theprocessing device are installed in the housing.